/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.octopus.yangj.customized.service;

import java.util.ArrayList;
import java.util.List;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.authc.*;
import org.apache.shiro.authc.credential.HashedCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.crypto.hash.Sha256Hash;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.octopus.yangj.generated.model.EmployeeRoleStruct;
import com.octopus.yangj.generated.model.EmployeeStruct;
import com.octopus.yangj.generated.model.RolePermissionStruct;
import com.octopus.yangj.generated.dao.EmployeeDao;

/**
 * The Spring/Hibernate sample application's one and only configured Apache Shiro Realm.
 *
 * <p>Because a Realm is really just a security-specific DAO, we could have just made Hibernate calls directly
 * in the implementation and named it a 'HibernateRealm' or something similar.</p>
 *
 * <p>But we've decided to make the calls to the database using a UserDAO, since a DAO would be used in other areas
 * of a 'real' application in addition to here. We felt it better to use that same DAO to show code re-use.</p>
 */
@Component
public class RealmService extends AuthorizingRealm {

    protected EmployeeDao userDao = null;
    
    @Autowired
    private LogService logService;

    public RealmService() {
        setName("RealmService"); //This name must match the name in the User class's getPrincipals() method
        HashedCredentialsMatcher matcher = new HashedCredentialsMatcher();
        matcher.setHashAlgorithmName(Sha256Hash.ALGORITHM_NAME);
        setCredentialsMatcher(matcher);
    }

    @Autowired
    public void setUserDao(EmployeeDao userDao) {
        this.userDao = userDao;
    }

    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authcToken) throws AuthenticationException {
        UsernamePasswordToken token = (UsernamePasswordToken) authcToken;
    	EmployeeStruct user = new EmployeeStruct();
    	user.setUsername(token.getUsername());
    	List<EmployeeStruct> list = userDao.findEqualByEntity(user, null);
        if( list != null && list.size() == 1 && list.get(0) != null) {
            return new SimpleAuthenticationInfo(list.get(0).getId(), list.get(0).getPassword(), getName());
        } else {
            return null;
        }
    }

    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
        Long userId = (Long) principals.fromRealm(getName()).iterator().next();
        EmployeeStruct user = (EmployeeStruct)SecurityUtils.getSubject().getSession().getAttribute("currentUser");
        if(user == null){
        	user = userDao.get(userId);
        	SecurityUtils.getSubject().getSession().setAttribute("currentUser", user);
        }
        if( user != null ) {
            SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
            for( EmployeeRoleStruct role : user.getRoles() ) {
                info.addRole(role.getName());
                List<String> permissions = new ArrayList<String>();
                if(role.getPermissions() != null){
                	for(RolePermissionStruct permission : role.getPermissions()){
                		permissions.add(permission.getCode());
                	}
                }
                info.addStringPermissions(permissions);
            }
            return info;
        } else {
            return null;
        }
    }
    
    public EmployeeStruct getCurrentUser() {
    	EmployeeStruct user = (EmployeeStruct)SecurityUtils.getSubject().getSession().getAttribute("currentUser");
    	if(user != null)
    		return user;
        final Long currentUserId = (Long) SecurityUtils.getSubject().getPrincipal();
        if( currentUserId != null ) {
        	user = userDao.get(currentUserId);
        	SecurityUtils.getSubject().getSession().setAttribute("currentUser", user);
        	logService.log("common", "login", null);
            return user;
        } else {
            return null;
        }
    }
    
    public boolean hasRole(String role){
    	return SecurityUtils.getSubject().hasRole(role);
    }

}

